I. Technical Field
The present invention relates to optical electronics. More specifically, the present invention relates to integrated optical electronics for use in optical communication and computing applications, wherein the integrated optical electronics are primarily fabricated in the form of monolithic semiconductor structures.
II. Background Art
Conventional integrated optics apparatus for communications or computation typically comprise active devices such as emitters, modulators, and detectors as well as passive devices such as resonators for filtering. These devices may range in size from relatively large glass reflectors and mirrors to microscopic semiconductor laser diodes. In any case, each device is generally a separate, discrete component. Therefore, assembling a complete optical communications or computation system comprising a combination of such devices requires physical integration at the component level of many different optical devices. Many disadvantages arise as a result of such component-level integration.
Most obvious is the difficulty encountered in assembling components to provide the extremely accurate alignments necessary for proper operation. The resulting misalignments greatly complicate coupling the plurality of devices to a single optical beam.
A further disadvantage of the prior art component-level architecture is its susceptibility to disalignment due to vibration and temperature fluctuation. Because the optical devices are merely interconnected and do not share a sufficiently substantial common structural support, they are likely to become disaligned or detuned from mechanical vibration or thermal expansion or contraction. Also, the materials of which resonant devices themselves are constituted expand and contract with temperature variations and also show variations in their indices of refraction. These properties cause detuning of resonators and result in wavelength variations in emitted and detected light.
To overcome the disadvantages of the prior art, it is therefore desirable to have a method and apparatus which provides for the integration of optical electronics in primarily monolithic dielectric and/or semiconductor architecture during the fabrication process.
It is further desirable to provide monolithic integrated optics whereby each optical device is very closely aligned to a common optical .axis so as to facilitate the coupling of all devices to a single optical beam or single mode optical fiber.
The novel method and apparatus of the present invention provides integrated optics which overcome the disadvantages of the prior art and further provide many significant new features and advantages.